﻿(function ($) {
	$.fn.lazyload = function (options) {
		var settings = { threshold: 0, failurelimit: 0, event: "scroll", effect: "show", container: window }; if (options) { $.extend(settings, options); }
		var elements = this; if ("scroll" == settings.event) { $(settings.container).bind("scroll", function (event) { var counter = 0; elements.each(function () { if ($.abovethetop(this, settings) || $.leftofbegin(this, settings)) { } else if (!$.belowthefold(this, settings) && !$.rightoffold(this, settings)) { $(this).trigger("appear"); } else { if (counter++ > settings.failurelimit) { return false; } } }); var temp = $.grep(elements, function (element) { return !element.loaded; }); elements = $(temp); }); }
		this.each(function () {
			var self = this; if (undefined == $(self).attr("original")) { $(self).attr("original", $(self).attr("src")); }
			if ("scroll" != settings.event || undefined == $(self).attr("src") || settings.placeholder == $(self).attr("src") || ($.abovethetop(self, settings) || $.leftofbegin(self, settings) || $.belowthefold(self, settings) || $.rightoffold(self, settings))) {
				if (settings.placeholder) { $(self).attr("src", settings.placeholder); } else { $(self).removeAttr("src"); }
				self.loaded = false;
			} else { self.loaded = true; }
			$(self).one("appear", function () {
				if (!this.loaded) {
					$("<img />").bind("load", function () {
						$(self).hide().attr("src", $(self).attr("original"))
[settings.effect](settings.effectspeed); self.loaded = true;
					}).attr("src", $(self).attr("original"));
				};
			}); if ("scroll" != settings.event) { $(self).bind(settings.event, function (event) { if (!self.loaded) { $(self).trigger("appear"); } }); } 
		}); $(settings.container).trigger(settings.event); return this;
	}; $.belowthefold = function (element, settings) {
		if (settings.container === undefined || settings.container === window) { var fold = $(window).height() + $(window).scrollTop(); } else { var fold = $(settings.container).offset().top + $(settings.container).height(); }
		return fold <= $(element).offset().top - settings.threshold;
	}; $.rightoffold = function (element, settings) {
		if (settings.container === undefined || settings.container === window) { var fold = $(window).width() + $(window).scrollLeft(); } else { var fold = $(settings.container).offset().left + $(settings.container).width(); }
		return fold <= $(element).offset().left - settings.threshold;
	}; $.abovethetop = function (element, settings) {
		if (settings.container === undefined || settings.container === window) { var fold = $(window).scrollTop(); } else { var fold = $(settings.container).offset().top; }
		return fold >= $(element).offset().top + settings.threshold + $(element).height();
	}; $.leftofbegin = function (element, settings) {
		if (settings.container === undefined || settings.container === window) { var fold = $(window).scrollLeft(); } else { var fold = $(settings.container).offset().left; }
		return fold >= $(element).offset().left + settings.threshold + $(element).width();
	}; $.extend($.expr[':'], { "below-the-fold": "$.belowthefold(a, {threshold : 0, container: window})", "above-the-fold": "!$.belowthefold(a, {threshold : 0, container: window})", "right-of-fold": "$.rightoffold(a, {threshold : 0, container: window})", "left-of-fold": "!$.rightoffold(a, {threshold : 0, container: window})" });
})(jQuery);